The present invention relates to an ultrasound diagnostic apparatus, and particularly, to a power supply method to an ultrasound probe of an ultrasound diagnostic apparatus that performs diagnosis on the basis of an ultrasound image generated by transmitting and receiving ultrasonic waves from a transducer array of the ultrasound probe.
The present invention also relates to measures against heat dissipation of the ultrasound probe.
In the related art, ultrasound diagnostic apparatuses using an ultrasound image are being put into practical use in the medical field. Generally, this type of ultrasound diagnostic apparatus has an ultrasound probe with a built-in transducer array, and an apparatus body connected to this ultrasound probe. Ultrasonic waves are transmitted toward a subject from the ultrasound probe, and the ultrasound probe receives ultrasonic echoes from the subject and generates an ultrasound image by electrically processing reception signals in the apparatus body.
In recent years, in order to eliminate the problems with a communication cable that connects the ultrasound probe and the apparatus body together and thereby improve operativity, an ultrasound diagnostic apparatus that connects an ultrasound probe and an apparatus body by wireless communication is being developed.
In such a wireless communication type ultrasound diagnostic apparatus, generally, a rechargeable battery is contained within the ultrasound probe as a power source, and when charging of the battery is required, for example, as in the apparatus described in JP 2002-530175 A, power is fed from a power supply part of the apparatus body to the battery in the ultrasound probe in a state where the ultrasound probe is housed in a probe holder set in the apparatus body, and an external charge contact of the ultrasound probe is connected to a contact on the side of the probe holder, or as in apparatuses described in JP 2010-233826 A and JP 2010-167083 A, power is fed to the battery in a non-contact manner by electromagnetic induction or the like from a power supply part of a power supply apparatus set around the diagnostic apparatus body or diagnostic apparatus.
However, in the apparatus of JP 2002-530175 A, in order to house the ultrasound probe in the probe holder of the apparatus body to charge the battery, there is a concern that ultrasonic diagnosis may need to be suspended when this battery is charged, and the ultrasonic diagnosis may be hindered. In the apparatus of JP 2010-233826 A, there is a concern that the distance between the power supply part set around the diagnostic apparatus and the power receiving part of the ultrasound probe may change according to an operator's standing position, or that it may become impossible to efficiently supply electric power to the ultrasound probe due to the influence of electronic devices or the like around the ultrasound diagnostic apparatus.
Additionally, the continuous running time of an ultrasound probe with a built-in battery is influenced by the capacity of the battery, and the exhaustion speed of the battery. Thus, in the apparatus described in JP 2010-167083 A, in order to enable prolonged continuous running, the amount of electric power remaining in the battery is checked. When the amount of electric power remaining is equal to or less than a threshold, a non-power-saving mode in which priority is given to the image quality of an ultrasound image is changed to a power-saving mode in which priority is given to the functions of the probe and the apparatus body, and the electric power to be supplied to the probe and the apparatus body is limited by the power-saving mode, thereby suppressing the consumption of the electric power of the battery.
However, in the apparatus of JP 2010-167083 A, if the electric power of the battery built in the ultrasound probe becomes equal to or less than a predetermined quantity even if the consumption of the electric power of the battery is suppressed by appropriately changing the non-power-saving mode in which priority is given to the image quality of an ultrasound image to the power-saving mode in which priority is given to apparatus functions, in order to replace the existing battery with a new battery or to set the existing batter at the diagnostic apparatus body to supply electric power to the ultrasound probe, there is a concern that the use of the ultrasound probe may be temporarily suspended. Additionally, even if an operator desires a high image-quality ultrasound image as being obtained in the non-power-saving mode during diagnosis in the power-saving mode, it is difficult to make a change to the non-power-saving mode from the balance with the exhaustion of the battery.
Additionally, the related-art ultrasound diagnostic apparatuses have also a problem regarding the generation of heat by the ultrasound probe.
In general ultrasound diagnostic apparatuses that transmit and receive ultrasonic waves from the transducer array of the ultrasound probe, thereby generating an ultrasound image, heat is generated from the transducer array as ultrasonic waves from the transducer array are transmitted. However, normally, since diagnosis is performed while an operator grips the ultrasound probe with one hand and brings an ultrasound transmission/reception surface of the transducer array into contact with the surface of a subject, the ultrasound probe is often accommodated in a small housing such that the operator may easily grip the probe with one hand. For this reason, the temperature in the housing of the ultrasound probe may rise due to the generation of heat from the transducer array.
Additionally, in recent years, there has been proposed an ultrasound diagnostic apparatus that reduces the influence of noise to obtain a high image-quality ultrasound image by building a circuit board for signal processing in the ultrasound probe, and transmitting reception signals output from the transducer array to the apparatus body by wireless communication or cable communication after being subjected to digital processing. In the ultrasound probe that performs this kind of digital processing, heat is generated from the circuit board even when the processing of the reception signals is performed, and in order to guarantee a stable operation of each circuit of the circuit board, it is necessary to suppress a temperature rise in the housing.
Thus, for example, JP 2006-158411 A discloses an ultrasound diagnostic apparatus configured so as to cool the ultrasound probe, using a cooling medium, such as water. A cooling medium circulation unit is mounted on a probe connector part that forms a cooling medium pipe along a cable connecting the diagnostic apparatus body and the ultrasound probe, and connects this cable to the diagnostic apparatus body, and a cooling medium is circulated between the probe connector part of the diagnostic apparatus body, and the ultrasound probe via the cooling medium pipe by the circulation unit, whereby cooling of the ultrasound probe is performed. However, in such an apparatus, there is a problem in that the cooling medium circulation unit needs to be mounted on the probe connector part of the diagnostic apparatus body, and the ultrasound diagnostic apparatus is complicated. Additionally, since the cooling medium pipe is formed along the cable that connects the diagnostic apparatus body and the ultrasound probe, the diameter of the cable increases and the flexibility of the cable deteriorates, and therefore, there is a concern that the operativity that is an important performance for the ultrasound probe may be adversely affected.